1. Technical Field
This invention relates to vacuum cleaner apparatus, and more particularly to a liquid bath vacuum cleaner having an improved separator of reduced dimensions for separating dust and dirt particles from dust and dirt entrained air ingested by the vacuum cleaner apparatus.
2. Discussion
Vacuum cleaners of various designs are used in residential and commercial settings for a wide variety of cleaning purposes. These appliances develop suction force to create air flow which picks up large and small dust and dirt particulates from the surface being cleaned. These particulates are then separated from the ingested air within the vacuum cleaner for later disposal.
One type of vacuum cleaner is a canister type which has a relatively stationary canister which is connected to a moveable wand by a flexible connecting hose. One particular design of canister type vacuum cleaner is known as a liquid bath type. This type of vacuum cleaner directs incoming air and particulates into contact with a liquid bath, which is typically water, which traps particulate matter such as dust and dirt particles entrained in the ingested air stream as the air stream impinges the surface of the liquid. A liquid bath type vacuum cleaner has a significant advantage in that its filtration mechanism is water, thereby eliminating the need for replaceable filters. Accordingly, only the water in a liquid reservoir of the vacuum cleaner needs to be periodically changed.
Numerous designs of liquid bath type vacuum cleaners are presently known. The following U.S. patents, the disclosures of which are hereby incorporated by reference, and all of which are assigned to the assignee of the present invention, relate to various improvements in liquid bath type vacuum cleaner systems: U.S. Pat. Nos. 2,102,353; 2,221,572; 2,886,127; and 2,945,553, and 5,096,475.
An important component of all liquid bath type vacuum cleaner systems is the separator. The separator is a component which is driven rotationally by the motor of the vacuum cleaner system to help separate dust and dirt particles from dust and dirt entrained air ingested by the vacuum cleaner system, which escape being trapped in the liquid bath of the system. Such separators typically are either cylindrical or conical in shape and include a relatively large number of slots formed in a sidewall thereof. The slots allow air to pass through the separator while it is being rotated at a relatively high speed, for example 10,000 rpm or higher, during operation of the vacuum cleaner system. Typically, 70 or more slots each having a width preferably on the order of about 0.040-0.080 inch, and more preferably of about 0.060 inch, are required so as not to overly restrict the flow of air through the separator. Restricting the flow of air reduces the vacuum force and thereby the efficiency of the vacuum cleaner. The drawback with including a relatively large number of slots, however, is that the overall dimensions of the separator must be relatively large. For example, separators in present day use have a diameter at the upper ends of their sidewalls which typically ranges from at least about 3.5 inches up to about 5 inches. This relatively large size necessitates a more powerful motor to drive it at the speeds it needs to rotate at to perform effectively.
It would therefore be highly desirable to provide a separator which is significantly smaller in diameter than presently developed separators, and more particularly a separator having a diameter which is less than preferably about 4 inches when measured at the upper end of the sidewall of the separator. The obvious drawback is that with such a smaller diameter separator, the number of slots must also be reduced. Reducing the number of slots reduces the airflow through the separator if the separator is driven at the same rotational speed as the larger diameter separator mentioned above. Thus, to compensate for the lesser number of slots in the smaller separator, such a separator would have to be driven at an increased speed, typically between about 20,000 rpm-30,000 rpm, to maintain the same quantity of airflow therethrough.
Driving the above-mentioned smaller separator at a higher rotational speed would normally not be a problem because motors capable of such speeds are widely commercially available. However, when driving a smaller separator at such a high speed, it becomes necessary to space the separator a considerable distance from the upper surface of the liquid and the liquid bath positioned below the separator. The increased spacing is needed because the extra high speed at which the separator is driven has been known to cause water to be "pumped" or drawn in from the liquid reservoir through the interface between the upper outer edges of the separator and the housing of the blower of the vacuum cleaner apparatus, which is generating the suction airflow through the separator. The entry of liquid into the interior area of the fan housing is highly undesirable because it can cause corrosion of the blades of the blower fan as well as reduce the airflow through the fan.
Prior attempts to remedy the above problem of drawing water into the interior of the fan housing when using a small separator (i.e., a separator having a diameter of less than about 4 inches) have involved spacing the lower end of the separator a significant distance from the upper surface of the water in the liquid reservoir in an attempt to reduce the amount of water drawn in around the separator. Spacing the separator farther away from the upper surface of the water, however, requires that the overall vacuum cleaner assembly be made considerably taller. The increased overall dimensions of the vacuum cleaner assembly contribute to increased weight of the product, as well as the need for increased or larger packaging materials and increased shipping costs.
It is therefore a principal object of the present invention to provide a vacuum cleaner assembly having a smaller separator with a fewer number of slots than has heretofore been employed in such machines, which does not require spacing the separator a greater distance from an upper surface of a liquid in a liquid reservoir than has previously been necessary.
It is still another object of the present invention to provide a separator having a reduced diameter and reduced overall height, and which is therefore lighter and which can be driven by a smaller motor, and which does not need to be spaced any further from the upper surface of a liquid in a liquid reservoir than present day larger separators to avoid drawing in liquid around the separator.
It is still another object of the present invention to provide a separator assembly which forms a labyrinth seal around a fan housing to prevent liquid from being drawn into the interior area of the fan housing when the separator is positioned closely adjacent an upper surface of liquid in a liquid reservoir of the vacuum cleaner assembly.
It is still another object of the present invention to provide a separator assembly which includes a separator having a reduced number of slots, and which may be operated at a higher rotational speed than previously developed separators, and which may also be spaced relatively close to an upper surface of a liquid in a liquid bath without drawing in liquid around the perimeter of the upper end of the separator during operation.